Drip-evaporating unit for air conditioners



Nov. 11, 1952' P, MQQRE 2,617,637

DRIP-EVAPORATING UNIT FOR AIR CONDITIONERS Filed Jan. 29, 1951 2 SHEETS-SHEET 1 Zmventor 7 Paul B. Moore In m Gttornegs Patented Nov. 11,1952 1? J:

' DRIP-EVAPORATING UNIT FOR AIR CONDITIONERS Paul B. Moore, York, Pa., assignor to York Corporation, York, Pa., a corporation of Delaware Application January 29, 1951, Serial No. 208,290

2 Claims. (01. 261-45) This invention relates to air conditioners of the portable type and particularly to means for evaporating in the condenser air-stream the drip water condensed from the evaporator air-stream. Re-evaporation of drip water is standard practice in this art and the present invention involves details of arrangement which assure reliable re-evaporation even under adverse atmospheric conditions.

When the relative humidity of the indoor air approaches saturation, the maximum amount of drip water is condensed on the evaporator and must be disposed of. The corollary is that because the outdoor air will then also be nearly saturated, it is most diflicult to re-evaporate the drip in the condenser air-stream.

The industry has established a test for portableunits such that the evaporator and the condenser are each subjected to air whose dry bulb temperature is 80 and whose wet bulb temperature is 78. A satisfactory device must operate continuously for six hours under such conditions without overflowing. It has been found that a device which would pass this test would fail under conditions which commonly exist at times in certain localities, for example, along the Gulf coast in Texas in summer. The device here disclosed is the only one known to applicant which has consistently passed this test.

According to the invention, means are provided to accumulate in the device a substantial quantity of drip water which is efiective to sub-cool refrigerant in the lower portion of the condenser and which takes up in the process a considerable amount of heat. Sub-cooling of condensed refrigerant is not new in this art, but it is one of the effects which in combination with others gives a high evaporation rate under unfavorable conditions.

Another important feature of the invention is that the housing is so contrived that up to the point of overflow, the only way that drip Water can leave the device is by re-evaporation. It is repeatedly sprayed until evaporated.

In the prior art, no eifort has been made so far as applicant is advised, to prevent the drip water from coming into contact with the blades of the condenser air fan. Where an ordinary bladed propeller type fan is used, there tends to be a back-flow in a zone immediately outside the path of the tips of the blades, and this back-flow will cause overflowing water to be thrown in all directions so that the fan becomes an active adverse factor. That action is inhibited by the arrangement of the fan within a fixed shroud, as is characteristic of the present invention.

To insure the necessary dependable performance, every detail has been refined.- The result justifies the extensive study and care which have been devoted to the problem.

A successful embodiment of the invention will now be described with reference to the accompanying drawings in which:

Fig. -1 is a view showing the condenser fan motor, the condenser air fan, the spray ring and the condenser in elevation with the housing and fixed shroud ring of the fan in vertical section.

Fig. 2 is an elevation of that side of the spray ring which is toward the fan. The fan blades are shown in broken lines to indicate the positional relationship between the spokes of the spray ring and the blades of the fan.

Figs. 3, 4 and 5 are respectively sections-on the lines 3-3, 4-4 and 55 of Fig. 2.

These conditioner units are based on a refrigerative circuit of the compressor-condenserevaporator circuit type. A typical example of the complete conditioner according to the prior art is shown in the patent to Moore 2,316,704, April 13, 1943. In the drawings of the present application only the condenser fan, the motor which drives it, the sump, the condenser and closely related parts are shown. It will be understood, however, that the conditioner unit includes a compressor and an evaporator connected in the usual circuit with the condenser. The drip water is moisture condensed from the room air on the evaporator, and is drained from the'e'vaporator to the sump for evaporation in the condenser cooling air-stream.

A portion of the drip connection is illustrated at H in Fig. 1. In that figure the sump appears at I 2. The condenser comprises a plurality of closely spaced vertical parallel fins I3. These are in thermal contact with the tubular passes of the condenser. The return bends l4 connect these tubular passes and are a part of them.

An electric motor l5 supported on a base It, drives a shaft I! on which is mounted a bladed fan 18 of the propeller type. The direction of rotation of the fan is indicated by an arrow in Fig. 1 and is clockwise when the shaft I1 is viewed from its lefthand end in Fig. 1. On the end of the shaft l1 and between the fan l8 and the condenser is the spray wheel. This comprises a hub l9 and four spokes 2| which extend radially to a circular rim 22. The spokes 2| are T-shaped in cross-section as indicated in Fig. 5 and the rim is L-shaped in cross-section as indicated in Fig. 4. The peripheral surface 23 of the rim is a cylinder as is clearly indicated in the drawings.

The relationship of the spokes 2| to the blades of fan I8 is important. As viewed in Fig. 2 the wheel turns counter-clockwise, the spokes and the fan blades are equal in number and the spokes have an angular lead as compared to the center line of the fan blades. Each spoke approximately bisects the angle between the leading edge'of and the radial center-line of the: correspondingbla'de. Asa practical matter-the'center line of the spoke leads the center line of the corresponding fan blade by an angle between 14 and 17. The angle is diagrammedin Eig. 2 and a legend stating the angular 'limitsis ithere applied.

The space above the sump. lzi-isitightly enclosed as shown. The forward portion-ofthe fan turns within a shroud ring formed-in part by the flanged portion 24 of a vertical'pa'rtition, and in part by an applied ring 25 whose interior-surface 26 is a cone flaring in the direction of air flow. The ring is attached to th partitionby screws which enter lugs .27. There may-bethree .or four such-lu-gs,-the purposebeing to-insure rigidity without seriously impedingthe" drainageof any water which m-ay dep'osit :on the router surface-of the ring 26.

The shroud ring defines the---entrance to the air path and aiio'rds g-radu-alcontraotion which diminishes; their'reverses and becomes" a, graduall expansion.

The diameter of theirimi 23-of the-sprayv wheel isvsuch-ithatthesump 2 will be filled nearlyiull, -(that:is to the level indicatedat A-A.),-When the. rim: first engages the 'surfa'ceof the-water in the sump. -Whenever the motor 15 :is running, the fan and.spray ring are both rotating, the ring atomizeswater from thebath, and the fan blows it into contactwith-the fins i3 of the condenser.

The shroud 24,- 25 :isefifectives tosmooth the air flow -.--and -keep water out-f contact withxthe blades of -the fani8. 'Because-of'this fact. and because ofthe fine atomization of" the water'by the.- spray wheel, a very--,goodaevaporative effect is secured.

Themotor runs-atlOOOrR-R Mhor .more.

Theispray wheel. isabout 12' in diameter. .Consequently thelineal-speedof itslrimris high. In the embodiment using-am" .spray ==wheel, the interval between the fins andthej proximateia-ce of the wheelis about %"'and:the interval-betweenthe fanblades and the proximate face-of the wheel is about These dimensions are typical and are subject to some variation. This is particularly true where the design of the fan or the size of the spray wheel is modified. The dimensions are given, not with the intention of expressing limitations, but with the idea of dis- :closing the dimensionsof one embodiment which hasproved"tQ be'succesSfuI.

I claim: 1. In a drip-evaporating device, the combinationof asump; means for supplying drip-water thereto; aj'finned condenser mounted above and partly in said sump, so as to deliver heat to water in the sumpzan'd so'that water draining from the fins of the .condenser and warmed by contact therewith, is caughtby the sump; enclosing walls defining an air path across said sump and out between the fins of the condenser; a propeller type fan mounted on a horizontal axis and posi- -tion'ed :.to1force air through said defined. path; a spray-wheel also i mounted -on ;a horizontal :axis and adapted"tocontactthe surface of wateriin the sump cbetween the fan zand the ..-condenser and:spray' water .-into.said,path in. a. part thereof beyond said.fan;..a fixeds'hroud ring defining :the entrance 'tozrsaid :air-cpatha.and reverselyiflared to aiTord a gradual contraction of the \air stTeam which gradually decreases .and beco'mes a gradual expansion of the stream;said' shroud being closely? spaced 5 from 1 the tra'ce'i'of the -fan blade tips at' the exit side of i the fan-and serving to resist peripheralreflux or air and xhea'nsfor rotating said ian and wheel.

2. 'The combination-defined in claim 1 in'whi'ch the exit face of the-fan is -within' the entrance portion of the shroudring and the stream-expansion portion of the ring extends beyond the face of thefan in the direction' of* air flow.

PAUL B MOORE.

' REFERENCES. CITED The following references are of're'cord' 'in .the file of this patent:

UNITEDSTATES PATENTS Number Name Date 1,955,269 Anetsberger et a]. .i Aprxlfl, 1934 2,091,159 Persons -Aug."24, 1937 2,194,711 Meyer 'et a1. Mar; 26;1940

- 2,219,826 Surnburne "et a1 O '3t.29; 1940 2538,879 -Newcomb et a1. i] an! '23,"- I951 

